House electric



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R. w. BAILEY TREATMENT 0F STEAM T0 REDUCEv OR REVENT CORROSION FiledDec. 1'?. 1921 2 Smets-sheet 2 ATTORNEY Patented Non.r 39, i926.,

naiss RCI-ARD-WILLAM BALEY, OF ALTRZ'GHAM, EEGLAND, ASSGNGR T0 WESTNG-HOUSE ELECTRIC 35 MANUFACTURENG COMPANY, A CQRPRATEON OF PENNSYL- VANEA.

TREATMENT 0F STEAM T0 REDUCE 0R PREVENT CGRRGSION.

Application filed December 17, 1921, Serial No.

Ihis invention relates to means for treating steam to reducel or preventcorrosion of apparatus or plants in which it isutilized and while it isapplicable generally to steam plants of various kinds, it is directedprincipally to the reduction or prevention of corrosion of the bladingin steamfturbines. f

With this object in view it has already been suggested to provide inconnection with steam turbines and other engin-es a corredible strainerthrough which steam'is caused to pass before entering the turbine orother engine, the steam in passing; lthrough the strainer coming into4contact with metals which so far as corrosion is concerned are similarto or not less acted upon than those of the turbine or engine parts inwhich the steam is to be'afterwards employed. It does not, however,appear to have been appreciated that corrosion of the metals in questiononly proceeds in the presence of moisture and the passing 4of dry steamthrough such a strainer as has been heretofore suggested would notnecessarily attain the result desired. I

- According to the present invention a device such as the corrodiblestrainer heretofore suggested is arranged to be located in the path ofthe steam from the boiler to the lturbine or other appliance at a pointwhere the steaml contains a sufficient amount of moisture to enable thedevice to be effective. Consequently, when the steam is superheatedbefore being used, the device or strainer will, according to the presentinvention, be located between the boiler and the superheater. Where thesteam at no part of its path is in a sufficiently vwet or saturatedcondition to obtain the most effective neutralization or lremoval of theactive corrosive elements contained in the steam, water may be injectedinto the corrodible strainer in the form of a fine spray or may becaused to trickle over the surface of the material provided in saiddevice or the steam may be partly condensed by passing it through adevice somewhat similar for example to a feed water heater lof thesurface type so that its moisture content is raised to the necessaryamount. Preferably, a steam drieror `separator is incorporated for thepurpose of removing excess moisture from the steam after 528,055, and inGreat Britain December 20, 192i).

Yit has been treated before its admission to the turbine or otherapparatus in which it is to be used.

To enable the invention tc be clearly understood it will now bedescribed with referenceto the accompanying drawings in which F ig. l isa diagrammatic sectional elevationof steam treating apparatus inaccordance with the invention, applied by way of example to a. watertube steam boiler; 2 is a sectional elevation of one form of the steamtreating apparatus sho-wing the parts thereof in greater detail and Fig.3 is a section on the line lll-HI of Fig. 2; Fig. i is a ysectionalelevation of another form of the steamk treating apparatus and Fig. 5 isa section on. the line VV of F ig. e. F 6 is a sectional elevation of. afurther form of the steam treating apparatus in accordance with theinvention. Fig. 7 is a sectional elevation lof a still further form ofthe steam heating apparatus, and Fig. 8 is a section on the lineVIIIe-VH1 of Fig 7.

Referring to Fig. l of the drawings, l is the upper 4.drum forming'partrof a common form of water-tube boiler, 2 and 3 indicaterespectively the front and back water tubes connecting thev said drum toa lower drum not shown, and 4: indicates a superheater which. isconnected to an off-take header 5 and an intake header V6.l rllhe latteris connected with a pipe which in the ordinary way terminates in aportion 8 shown in dotted lines within the upper portion of the shell ofthe boiler above the water level therein. The steam treating apparatusin accordance with-the present invention is indicated at 10 andcomprises a drum or casing ll ofcylindrical, rectangular or other shapehaving its ends closed, kfor example, by caps l2 and 13. rlhe treatmentmaterial indicated at le consisting of iron plates e2:- panded sheet,turnings or the like for eX- ample, is arranged substantially in thecentral portion of the casing 11. The casing 1l is convenientlysupported on the top ofthe upper drum l of the boiler and is connectedwith the latter through a pipe 15 through which the steam passes fromthe drum l into the casing' ll thence passing upwards through thetreatment material lli and leaves the said casing by means of an outletpipe' 16 sar which is connected directly to the pipe 7, the portion 8being dispensed with. In the case, however, of a new boiler Ahaving'.t-he treater apparatus lin accordance with the'invention usedVtherewith, the pipe 16 may be connected to theinlet header 6 or' the.superheater 4 in any'V convenient manner.

Steam in a comparatively wet condition enters the treater .10 throughVthe pipe and coming` into contact with the treatment material 14corrodes the latter and its corrosive constituents are thereby reduced.

`case the steam doesy not possess sufficient moisture content for propercorrosive action with the treatmenty material 14,. the incoming steammay be artificially wetted byfmeans of a spray device 17 arrangedimmediately above the treatment material 14Y and :supplied with waterthrough a pipe 18 from any conve-nient so-urce. TWater from `thespraying device-17 will trickle over the surface loi the treatmentlmaterial 14 and drip into the bottom ot the-'casing 11. A pipeconnection 19v with a submerged discharge is provided* between the lowerpart of' the casing 11 and the drum 1 of the boiler by Cil which watercollecting in thebottom ol' the vcasing" is passed into the boiler. Saidpipe has an inlet 20, which is at a lowerlevel than'the inlet ofthe pipe15 into the casing I 11, but some distance from the bottom'thereof,sothatv the latter can serve as a receptacle for anyfdepositl or debriswhich may fall fromV the treater. Vilitliin 'the upper Vpart ofthecasingis preferably arranged a separator 21 oil any we-lllrno-wntypethrough which thev steam passes before leaving by the outlet pipe 16.This separator- 2.1 serves to remove the excess moisture 'from the steamand may advantageously ltake the same form as thetreaterA andV comprisesimilar'materialso that inl addition to the steam being-i drred'theiebv,further or more complete removal of the corrosive constituents oil thesteam some'o'f which may havebeen added to the steam by thewatersupplied for moistening it, takes place in the drying orseparating'process.

Rer'erringl to the detailed and preferred construction of the `treaterillustrated in Figs. 2 `and 3, the treatment material 14 is in ther formoif'a plurality' of rectangular .plates ar angedparallel'with oneanother in Fig. 3) then passes dmvmvards beneath the lower edges oi thewalls of the `iframe and therceupwzerds as show-ahy the arrow 2G throughthe plates oi .the treatment material 14. The .steam drier or separator2l is preferably ol similar construction to the treater 14 and isprovided with an openended rectangular trame 27 having'v a flange 28 atits lower edges resting upon an internal flange 29 within the drinn oreasing 11. The steam passes upwards through the treate-r` 14 and thedrier 2land thence passes as shown by the arrows 30 over the top edgeof' theV frame 27 and leave` the casing 11l by vhe outletV pipe 16. rlheactionzofthisfform of thetreating"apparatus is the-saune as that of theapparatus otlligl 1. The steamenters by the inlet pipe lfandis.deflected by the vertical sides of the frame 22, its speed beinggreatly decreased owing to the largetcrosssectional area of its path;rllhe velocity of t'he'steam after enteringthe outlet pipeli isincreased owingto the reduction ofthe sectional *area` of thel passagesthrough which it passes. luthis manner a relatively low steam -speedthrough the -apparatus is 0btained and the tendency to disturbance atthe entrance of thetreatment materiali Ais reduced. rlhe .method ofsupporting the ii'raines22 and 27 uponiianges as described, permit: thetreatment material to be readily renewedvor cleaned. lt will beunderstood that instead o 'f rectangular platesthe said frames maycarryV expanded or" perforated plates arranged 'horizontally orvertically or iron turnings may be used.v Furthermore,-

the plates or the like may be arranged in groups or sections orhorizontal layers. Or 1 ne plates may be inclined and so arrangedl Vthatsteam 1s caused to take a`z1gzag path through the apparatus.k

Referring now to the construction' of the apparatusillustrated in Figs.4 and 5, the casing'll is here arranged vwith Aits aXiSsUbstantiallyhorizon-tal and supported on .the top of thefdrum 1 of the-boiler in anyconvenient manner. The treatment mat'erial'14 consisting of iron plates,for example, isI arranged within a Aframe 31 which is rectanvguiar inhorizontal cross sectionand as before, is open atthe top `and bottom.The said" frame is cut away, as'clearly shown, in a Aslanting directiontowards the ends so as vto er1-pose the vertical edges of the plates andis provided with flanges substantially in the centre of the two sidesthereof' which are parallel-with the axis of the casing. The iianges 32rest upon horizontal webs 33' arranged within the casing 11 as clearlyshown in Fig. 5. The casing is provided with a partition which litsaround the right hand end of the upper partoii the frame 31 to provide'a substantially steam-tight joint there with as shown at 34 in Fig.. 4.A similar partition 35is arranged in they lower part' of the other endof the casing 11 and tits around the-lower part of the :trame 31 alsoproviding a substantially steam-tight joint therewith. These partitionsalong with the ianges 32 and 33 cause the steam entering by the inletpipe 15 and leaving by the outlet pipe 16 to assume the -path indicatedby the arrows, that is, the steam passes upwards through the space inthe left hand end ot the casing 11 and thence passes downwards andlaterally into the treatment material 14. The steam then leaves theplates of treatment material 14 in a 'downward and lateral direction andpasses upwards through the space at the right hand end of the casing 11leaving by the pipe 16. The spraying device 17 is provided above thetreatment material and the outlet pipe 19 is arranged in the mannerdescribed with reference to Fig. 2, a valve 36 being provided in saidpipe it desired. The

end covers 12 and 13 being removable, en-l able the interior oi. thecasing 11 to be inspected and permit the withdrawalofthe frame 31containing the treatment material.

In the arrangement illustrated in Figs. 4 and 5, no drier or separatoris shown but a separate drier may be employed it desired, In theapparatus of 6, however, a steam drier yor separator is provided in thefollowing manner. The frame 37 containing the treatment material 14 issomewhat similar to the frame 31, described in connection with Figs. 4and 5 excepty that the side walls abo-ve the flanges 32 are not cutaway, the side walls below the flanges 32 being cut away at 38 and 39 ateachend as shown. rlChe drum or casing 11 is provided with twopartitions 40 and 41 fitting around the upper portion of the two ends ofthe casing 37 and with a third partition 42 fitting around the lowerpart of the casing 39 and located a suitable distance along the saidcasing from the inlet end. lVith the above described disposition of thepartitions 40, 41 and 42, the steam entering by the inlet pipe 15 iscaused to pass upwards and laterally into the treatment material 14 intoa space 43 in the upper portion of the drum 11 between the partitionsand 41 and thence downwards through the treatment material21 separatedfrom the treatment material 14 by the lower partition 42 andconstituting the steam drier or separator. The steam leaves the platesof the treatment material 21 downwards and laterally and passes in thespace into the right hand endof the drum 11 and thence outwards throughthe pipe 1 6. It will be understood that by suitably disposing thepartitions 40, 41 and 42, the steam may be made to pass downwardsthrough the treater 14 and upwards through the drier or separator orupwards through both of these devices. This arrangement possesses theadvantage that any corrosive constituents liberated by the spray arecarried over the surface of the treatment material by the steam and areneutralized later, and since the steam passes upwards through the drier21, a more complete separation of the water from the steam may beobtained.,

it will be understood that the outlet pipe 19 instead or" beingconnected to the end covers 13 may be connected with the lower surtaceof the drum as shown in Figs. 1 and 7. In this way the end covers areleft free from any connections and can thus be readily removed.

Referring to the arrangement illustrated in Figs. 7 and 8, the drum orcasing 11 is provided with a horizontal web 44 extending completelyaround its inner walls. A vertical partition r45 extends upwards fromthe lower part ot the drum or casing 11 as tar as the said web 44 anddivides the lower part of the casing into two compartments 46 and 47,one of which is larger than the other as shown.` The larger compartment46 contains the treater 14carried in a rectangular frame 48 and provided`with a tiange 49 which is adapted to rest upon the web 44 and at oneend upon the upper end of the partition 45. The smaller compartment 47contains a drier or separator 21 carried in a rectangular frame 50provided with flanges 51 resting upon. the web 44 and at one end alsoupon the upper end ot' the partition 45. The treatment compartment 46 isprovided with lateral inlet openings 52 connected with the inlet pipe 15by means ot passages 53. The openings 52 are arranged below the web 44so that the steam entering the pipe 15 passes beneath the lower edges ofthe trame 4S and thence upwards through the treatment material 14 insaid trame. On leaving the treater-the steam passes over the upper edgesof the trames 48 and 50 and ot' the partition 45V and thence downwardsthrough the drier or separator 21 into the space beneath the web 44 inthe compartment 47. The steam leaves the latter compartment throughlateral openings 54 communicating by passages 55 with the outlet pipe16. The spraying device 17 is provided over the treater 14 in the manneralready described. The water outlet pipe 19 is provided as before todrain the water from the treatment compartment 46 into the boiler orelsewhere and a pipe 56 is provided for draining away any water that mayaccumulate in the separator compartment 47.

It will be understood that various valves such as indicated at 57 and 58in Fig. 4 may be provided for isolating the treating apparatus andsuitable by-passes, not shown, sov as to'permit the boiler to supplysteam direct in the event of the said apparatus being out of order andalso to permit it being opened up for inspection or other purposes. lncarrying out the invention the material employed in the anti-corrosivedevice or Y steain, and means for injecting a spray orl strainer inay beot various kinds andY the invention is not li-niited; to aspecicinaterial o-rtliis purpose. ln' the case oi* steam turbines havingsteel bla-des,-l oneniaterial which is very suitable 'for the purpose issheet iron or expanded sheet steel or a light network of steelor steeltui'iiings offering anr extend ed surface inay'be employed as alreadydescribed. ylllliere water-is injected into the apparatus for thepurpose of' increasing the moisture content oi'tl'ie steam, a portion ofthe boiler t'eed may be employed at the tenr.

peratnre at 'which it enters the boiler, the

quantity being arrangedv to be definite fraction of the total lfeed.

Having non'V particularly desfribed and ascertained the nature ofA inyksaid'invention andf in What inaiiner the saine is to be performed, Ideclare that what I claiin is :m

l. .Inra Vsteani generating plant, the coinloination oi a steam conduit,a corrodible strainer interposed in the steani conduit for separatingthe corrosive contents froml the Water into 'tlie corrodible strainer.

2. n afsteani generating plant, the coin-A bination et VaV steamconduit, a corrodible strainer interposed in the steain conduit forVseparating the corrosive contents ironi the steain, 'means forinjecting a spray or' Water into tlie'corrodible strainer, andA aseparator for drying the stearn after Dassin@ through .l to b o tli e1corrodible strainer.

in a stearn` generating plant, the coinbination oit a steam conduit, acorrodible Y strainer comprised of a plurality of elenients ofcorrodible materialV arranged parallel and in closely spaced relationfor separating the corrosive contents from vthe steain, means foreffecting a flow of steamiiiV onedirection throughtl'ie corrodilile,vstrainer,

andlineans for introducing a sprayot Water into tlie vstrainer insiichal manner that it trieldes over tlie elements in av direction oppositethe 'steani flow, and a separator for drying the steam Vaiter passingthrough the corrodible strainer;

In combination, a conduitl'for conveyj ing steani, a corrodible strainerinterposed in the conduit and coniprised of a'plurality of plates oi'inorrodible nia-terial arranged in parallel-and inclosely spacedrelation, means eliectiiig a ii'ow oi' steani in one direotionbetweenthey plates, nieaiis or'injecting Water tien, between the plates,ineansi'oi" inject ing water into the strainer and eif'lectingfa :Flowthereof between the plates in a direction opposite tothe steain flow,means vfor.

.draining the Water injected into the strainer including nieans forcollecting foreign vInater introduced with' the Water, and a separator-lfer drying the steani after passage through the strainer. i

ln testimony whereof, I Vhave hereunto subscribed niy naine this 24thday of No- Aveniber 1921.

RICHARD ll/YILLIAM BLEY

